Ronidazole for Dogs and Cats: Uses, Dosage, and Side Effects
Ronidazole is a prescription antiprotozoal medication that veterinarians may prescribe to treat certain intestinal protozoal infections in dogs and cats when first-line treatments have not been successful.
Because ronidazole is not FDA-approved or commercially available in the U.S., it is typically obtained through a veterinary compounding pharmacy.
Here’s how ronidazole works, when it’s prescribed, possible side effects, dosing guidance, and important safety information.
Key Takeaways
- Ronidazole is used to treat certain intestinal protozoal infections in dogs and cats.
- It is commonly prescribed for Tritrichomonas foetus in cats and Giardia in dogs when other treatments are unsuccessful.
- Ronidazole is not FDA-approved or commercially available in the United States and is typically obtained as a compounded medication.
- Neurologic side effects are the most important adverse effects to monitor for.
- Always give ronidazole exactly as directed by your veterinarian.
What Is Ronidazole?
Ronidazole is a prescription antiprotozoal medication used to treat certain intestinal protozoal infections that cause diarrhea in dogs and cats.
Veterinarians may prescribe ronidazole as an alternative treatment for:
- Tritrichomonas foetus infections in cats
- Giardia infections in dogs when first-line treatments have not been successful
Ronidazole is not FDA-approved or commercially available in the U.S. In some cases, your veterinarian may prescribe a compounded formulation prepared by a reputable veterinary compounding pharmacy.
Compounded ronidazole: Your veterinarian may recommend a compounded formulation when:
- Your pet has difficulty taking the commercially available formulation.
- The required dosage strength is not commercially available.
- Your pet is allergic to an ingredient in the available medication.
Compounded medications are not FDA-approved. They are prepared by a veterinarian or licensed pharmacist to meet an individual patient's specific needs.
Safety considerations: Ronidazole should not be used in pets that have had a sensitivity or allergic reaction to ronidazole or other medications in the same drug class, such as metronidazole.
Before starting ronidazole, tell your veterinarian about all of your pet's medications and medical conditions, as drug interactions may increase the risk of side effects.
Ronidazole should not be used in farmed animals.
How Ronidazole Works
Ronidazole works by damaging the DNA of certain protozoal parasites, causing them to die.
Protozoa are microscopic, single-celled parasites that can infect the gastrointestinal tract and cause disease. Ronidazole belongs to the 5-nitroimidazole class of medications.
Like metronidazole, it kills susceptible protozoa by generating free radicals that disrupt the parasites' DNA.
How To Give Ronidazole
Give ronidazole exactly as directed by your veterinarian.
Ronidazole may be given with or without food, although giving it with food may help reduce the risk of digestive upset.
Important: Do not use ronidazole in pets with a known sensitivity to ronidazole or other 5-nitroimidazole medications, such as metronidazole.
Missed a Dose?
If you miss a dose of ronidazole, contact your veterinarian for guidance. In many cases, they may recommend giving the missed dose when you remember.
However, if it is almost time for your pet's next scheduled dose, they may advise skipping the missed dose and resuming the normal dosing schedule.
Do not give extra or double doses.
Ronidazole Side Effects
Ronidazole can cause side effects, particularly those affecting the nervous system. Contact your veterinarian if you notice any of the following signs:
- Fever
- Loss of appetite
- Loss of balance or difficulty walking
- Muscle tremors or weakness
- Seizures
- Low energy (lethargy)
- Uncontrolled eye movements (nystagmus)
Human Side Effects
Ronidazole is a prescription medication that is not FDA-approved for use in humans.
When handling ronidazole:
- Avoid direct contact with the medication.
- Wear disposable gloves when administering ronidazole.
- Wash your hands thoroughly after handling the medication.
- While your pet is taking ronidazole, wear disposable gloves when cleaning up waste or handling the litter box.
- Seal pet waste in a plastic bag and dispose of it according to your veterinarian's instructions.
If you accidentally ingest ronidazole, contact your physician, seek medical attention, or call the National Poison Control Center at 800-222-1222.
When To Call Your Veterinarian
Contact your veterinarian if:
- Your pet develops severe side effects.
- Your pet's condition worsens or does not improve with treatment.
- You suspect your pet has received an overdose.
- You have additional questions or concerns about using ronidazole.
Ronidazole Overdose
A ronidazole overdose can cause serious neurologic side effects and requires immediate veterinary attention.
Signs of an overdose may include:
- Loss of balance
- Difficulty walking or climbing stairs
- Muscle tremors
- Muscle weakness
- Seizures
- Uncontrolled eye movements (nystagmus)
If you suspect your pet has received an overdose, contact your veterinarian immediately, seek emergency veterinary care, or contact an animal poison control center. Consultation fees may apply.
- Pet Poison Helpline: (855) 764-7661
- ASPCA Animal Poison Control: (888) 426-4435
How To Store Ronidazole
Store ronidazole according to the pharmacy label to help maintain its safety and effectiveness.
Storage instructions:
- Always follow the storage instructions provided by the pharmacy.
- Keep the container tightly closed to protect the medication from moisture and light.
- Keep out of reach of children and pets.
Ronidazole for Dogs and Cats FAQs
Where can you buy ronidazole for cats and dogs?
Ronidazole is not FDA-approved or commercially available in the U.S.
In some cases, your veterinarian may prescribe a compounded formulation prepared by a reputable veterinary compounding pharmacy.
What is ronidazole used for in cats and dogs?
Ronidazole is used to treat certain intestinal protozoal infections in dogs and cats.
Veterinarians commonly prescribe it as an alternative treatment for Tritrichomonas foetus infections in cats and Giardia infections in dogs when first-line treatments have not been successful.
How long can you keep a cat on ronidazole?
There is no standard treatment duration for ronidazole in cats.
Treatment commonly lasts about two weeks, but the length of therapy depends on your cat's response and clinical signs, which may take months to fully resolve.
Your veterinarian may recommend follow-up diagnostic testing to confirm the infection has been successfully treated.
Can ronidazole be given with food?
Yes. Ronidazole may be given with or without food, although giving it with food may help reduce the risk of digestive upset.
Is ronidazole FDA-approved?
No. Ronidazole is not FDA-approved or commercially available in the U.S. and is generally obtained through a veterinary compounding pharmacy.
What infections does ronidazole treat?
Veterinarians prescribe ronidazole to treat intestinal protozoal infections, including Tritrichomonas foetus in cats and Giardia in dogs when preferred treatments have not been successful.
No vet writer or qualified reviewer has received any compensation from the manufacturer of the medication as part of creating this article. All content contained in this article is sourced from public sources or the manufacturer.
